Bangkok: A Myanmar military plane carrying more than 100 people is believed to have crashed in southern Myanmar.

The plane was carrying 120 people, including 106 passengers - mostly families of military personnel - and 14 crew.

The Chinese-made plane disappeared while flying over sea from the town of Myeik, a city on an island in the Andaman Sea, to Yangon.

There were fears it may have crashed into the ocean. Several reports from Myanmar said debris had been sighted in the sea, while BBC correspondent Jonah Fisher tweeted there were unconfirmed reports of survivors being found among wreckage.

In a statement posted to Facebook, commander-in-chief of the country's army Min Aung Hlaing said the flight took off from Myeik at 1:06 pm (local time) and contact with it was lost at 1:35 pm, when it was believed to be about 32 kilometres to the west of Dawei, formerly known as Tavoy.

It said Myanmar had received the plane in March last year, and since then it had logged 809 flying hours.

In a second announcement Wednesday night, the commander's office said six navy ships and three military aircraft were searching for the missing plane.

"We don't know what exactly happened to this plane after the loss of contact," said Kyaw Kyaw Htey, a civil aviation official at Myeik airport.

He said the weather had been "normal" with good visibility when the plane took off.

The plane is a Shaanxi Y-8 designed and manufactured by China's Shaanxi Aircraft Company.

The Y-8 is used for military and commercial operations, including as an air ambulance.

The aircraft is capable of operating in all weather conditions and can take-off and land on unprepared airstrips or runways including grass, snow and mud.

With agencies